Compatibility of an Aluminium-Silicon metal alloy-based phase change material with coated stainless-steel containers

•The effectiveness of a BN-based coating material for preventing corrosion of stainless steel by molten Al-Si alloy PCM is evaluated.•The PCM is characterized and then tested with coated stainless-steel crucibles.•The experimental results show that the coatings were stable for 720 melting and solidification cycles which simulates about two years of continuous operation of the TES system.•No signs of chemical degradation were observed on the coating material indicating its suitability for long term application.•In addition, the PCM latent heat remained unchanged after interaction with the coating for 720 cycles. Thermal energy storage (TES) using metal alloys as phase change material (PCM) is a promising technology for generating cost-effective dispatchable power from concentrated solar power (CSP). However, the containment of a metal alloy PCM is challenging due to the corrosivity of molten metals to metallic containers at the high operating temperatures targeted in next-generation CSP plants. Ceramic based protective coatings could be used to extend the lifetime of metallic containment materials, such as stainless steels, in direct contact with molten metal alloy based PCM. This work investigates the corrosion prevention performance of a boron nitride-based coating on stainless steel exposed to molten Al-Si alloy. The coating was effective for corrosion prevention and stable after 720 successive melting and solidification cycles.